Ink mill



Feb. 1, 1938. c. R. RECHTIN ET AL 2,107,214

INK MILL 2 Sheets-Sheet l Original Filed Sept. 24, 1934 Elmo/"Mi, flare/ice Becki/n Richard O/amJch Feb. 1, 1938; QRRECHTM 2,107,214

INK MILL Original Filed Sept. 24, 1934 2 Sheets-Sheet 2 Patented Feb. 1, 1938 UNITED STATES PATENT OFFICE INK MILL Application September 24, 1934, Serial No. 745,296 Renewed November 19, 1937 26 Claims.

This invention relates to a mill such as may be employed in the manufacture of inks, paints, and similar substances.

An object of the invention is to provide a mill of the character stated, with means to facilitate cleaning the rolls thereof when necessary.

Another object of the invention is to provide such a mill embodying roll displacing means for the above purpose, which means, when actuated,

19 will not necessitate a subsequent micrometric resetting of the mill rolls.

A further object of the invention is to provide a mill of the above stated character, with roll supporting and adjusting means so constructed and arranged that an accurate setting of the rolls is secured and maintained even though the working parts of the mill become worn by reason of long or hard usage.

A further object of the invention is to provide a mill of the character stated, which is simple, durable, and relatively inexpensive, and which may be operated easily and properly by operators not specially skilled in the art.

The foregoing and other objects are attained by the means described herein and disclosed in the accompanying drawings, in which:

Fig. 1 is a side view of the machine of the invention, the side cover plates being omitted.

Fig. 2 is a fragmental cross-sectional view taken on line,2--2 of Fig. 1.

Fig. 3 is a fragmental cross-sectional view taken on line 33 of Fig. 1.

Machines of the general character herein disclosed have been used for grinding pigment and similar substances in the manufacture of inks and paints. The prior machines, however,- were difficult to control, and whenever it became necessary to clean the rolls thereof or to separate the rolls 'for any reason, the micrometric setting of 0 the rolls was destroyed and had to be skillfully restored before the mill could be again placed in service. The present invention contemplates the use of novel means for preserving the micrometric setting of the rolls even though the rolls be shifted relatively for cleaning or other purposes, said means being adapted also to facilitate the cleaning andre-setting operations; The means herein disclosed have the further advantage of automatically compensating for normal wear of the machine elements, so that accurate adjustments are assured during the entire life 0 the machine.

' The machine of the inven on comprises a;

frame having spaced parallel uprights or standards Land 5 between which are .disposed ..the

, series of rolls 6, I, 8, 9, and i0. Inthe' operativ condition. of the machine, the successive rolls are in line, contacting relationship, adjusted sothat adjacent rolls contact each other with a pressure that is uniform along the full length of the rolls. The adjustments between rolls are very fine and accurate, so that a fine grinding action between successive rolls is attained. The adjustments may be progressively closer in. the direction of the final or discharging roll l0, so that the product may be removed from the final roll In in any suitable manner, suchas by means of a scraper l2, in a finished finely divided condition.

While the accompanying drawings show a machine having a group of five rolls, it is to be understood that the rolls may be increased or decreased in number, depending upon the nature of the material to be treated and the characteristics to be imparted to the finished substance.

The pair of horizontal rolls 6 and 1, which are the feed rolls for material to be transferred to the rolls 8, 9 and I0, may be more or less conventionally supported near the base of the machine. As disclosed, the rolls 6 and I have concentric axles l3 and M, the opposite ends of which are supported in suitable bearing blocks l5 and 16. The opposed bearing blocks l6 may be stationarily mounted in the frame whereas the pair of bearing blocks l5 may be slidably mounted in Ways or guides I I. springs l8 may be provided for the p pose of normally urging thebearing blocks apart while a Two or more compression screw l9 provided with a hand wheel or other actuating means 20 serves as a means for moving roll 6 toward roll 1. The direction of rotation of rolls 6 and l is indicated by the arrows applied theretol The rolls 8, 9- and Ill may be referred to as transfer rolls, roll 8 being in substantial contact with feed roll I and with the cooperative transfer roll 9. The roll 9 is in turn disposed for normally contacting the upper roll ill.

Each of the rolls 8, 9 and I0 is provided with a means for'displacement thereof to an inoperative position for cleaning and other purposes and with a means for effecting accurate micrometric setting relative to the next adjacent roll. Inasmuch as the displacing and adjustingmeans for each transfer roll operate upon the same principle, and comprise similar elements arranged merely in a. reversed order, a detailed description thereof relating to one transfer roll will sumce for the others also; I with reference to Figs. 1 and 2, the character 2| indicates an eccentric box for the L shaft end. 22 of roll I 0. Bearing boa 2| may be supported within a circular'opening 23 provided in the vertical standard 4 of the machine frame, the opening and the circular bearing box being so related that the bearing box may freely be rotated within said opening. Fig. 1 shows the normal contacting position of roll ID with roll 9, and in this position the axis 24 of shaft 22 is offset relative to the true center 25 of the bearin'g box. The centers 24 and 25 normally lie in a horizontal plane which includes that diameter of bearing box 2| which includes the axes 24 and 25. From the foregoing, it will be understood that a rotational movement of the eccentric bearing box 2| in a counter-clockwise direction about its true axis 25, will result in lifting the shaft 22 and itsassociated roll |0 from contacting relationship with the subjacent roll 9. In a like manner, roll 9 may subsequently be lifted from its position upon roll 3, and roll 8, in turn, may be lifted relative to the feed roll I. The characters 26 indicate merely pairs of arcuate retaining means or end-thrust'plates for maintaining the eccentric bearing boxes in their respective open ings 2|.

Each of the eccentric bearing boxes has operatively connected thereto a roll displacing means comprising amicrometric adjusting screw,- which screws'are designated by the characters 21, 28 and 29. The free or inner end 30 of each screw is threadedas indicated at 3|, the threads being received by the cooperating threads of a nut 32 which is pivotally connected tothe bearing box as indicated at 33. While any suitable means may be employed for pivotally mounting the nut relative to the bearing box, there is disclosed in Fig. 2 a crank member or eccentric mounting means 34 which is fixed relative to the eccentric bearing box. The member 34 may have a hub 35 which serves to maintain suitable anti-friction bearing means in position within the bearing box and about the shaft end 22; The member 34 may include also suitable packing rings 31 as shown,

. element 34.

for precluding escape of lubricant from bearings. A sleeve 38 may be provided for clamping the race of the anti-friction bearing 36 and for spacing a driving gear such as 39 from the crank The gear may be keyed or otherwise flxed to the shaft end as indicated at 49. For a purpose to be hereafter. explained, the threaded endof each micrometer screw has fixedly but adjustably mounted thereon, at opposite sides of the nut 32, the limit collars 01'' stops 4| and 42, each of said collars or stops being spaced slightly from the opposite ends of the adjacent eccentric has a bearing box 41 disposed about the periphery thereof, so that the cam my rotate therein without rotating the bearing box. Each bearing box is provided with a smooth bore 49 which rotatably receives the unthreaded shank of amicrometricadiusting screw'2l, and the screw is. precluded from longitudinalmovement in said 'bore means of-collars or,: the like 49 and II which secured to. the-screw shank.-

At accessible locations along th'e shaft and preferably near the vertical standards of the frame, the shaft-has fixed thereto one or more hand levers adapted to move in unison by reason of the connection with the cam shaft. Each hand lever is provided with an adjustable stop which-may be in the form of a screw 52 movable with the hand lever and adapted tocontact a stationary lug 53 carried by the frame of the machine. The adjustable stop means limits the downward movement of the hand lever, and determines the limit to which the cams or' eccentrics 43 and 44 may berotated in counter- It-is to be observed that the several pairs of roll-spacing cams 43 and 44,0f the rolls 8, 9 and Ill, may be made progressively larger or otherwise constructed to .impart a greater movement to certain of the rolls in order to permit spacing of the rolls from one another. For example, the throw of the uppermost pair of cams may approximate the one below, A,", and of the third pair, 34;", thereby to'allow substantially uniform spacings of approximately ,4," between all rolls when they are disposed in the inoperative or displaced positions. The distances or spacings above recited are by wayof example only, to clarify the description, and it is by no means intended to limit the invention to the specified distanc of cam throw mentioned. The throw of the' cams may be determined by their eccentricity rather than by their size, if desired. It is noteworthy that the cams or eccentrics 43 normally provide positive automatic locks, for the rotatable roll bearings, due to their dead-center disposition as illustrated in Fig. l. Attentionis now directed to the fact that the heel of the eccentric 2| which provides the bearing box for roll I, faces the front of the machine, as does also the toe of the corresponding eccentric which provides the bearing box for roll 9. The correspondingeccentric for roll 9 is disposed similarly to that of roll Ill. It is therefore evident that one pair of eccentrics is reversed relative to the other two pairs,- so that a lifting movement of roll ll may be effected by rotating the eccentric bearing boxes thereof in counterclockwise direction (this being true also of the bearing boxes of roll 8), while a clockwise rotational movement is required of the bearing boxes of roll 9 in order to elevate roll 9 to the displaced or inoperative position. The re-.-

versed positions of the eccentric bearing boxes .as just described precludes all possibilityof any back lash that would otherwise result from r0- tation of the rolls'and their driving gears ;in opposite directions, as will be explained hereinafter. The construction provides also for maintaining the axes .of all the transfer rolls in a common plane.- Because of the peculiar disposition of the eccentric bearing boxes as abovedescrlbed, it is necessary to dispose the pairs of cams 4344 of the quick-a ting displacing means v also inureversed and; staggered relationship, as shown id ms. '1. In order that n the hand aliens-n maybe rotated in the same direction to increase;

the pressure between furnished on the micromcti lc adjustment screws mlls, left-hand threads are 21 and 29, whereas right-hand threads are provided on the remaining screw 28. This construction eliminates any possible confusion in adjusting or resetting of rolls.

By means of the construction above described there is secured and maintained always an accurate setting of the rolls due to the fact that the rotational movement of each roll tends always to rotate its associated eccentric bearing box, with the result that the threads of the micrometer screws and the threads of their cooperative nuts, can have no play or lost motion therebetween. The normally fixed stops or collars 4i and 62 which were referred to previously permit only one or two turns of the micrometer adjustment screws within the nut or nuts 32, thereby preeluding any exaggerated maladjustment of the rolls by means of the hand wheels. .The characters 51 and 58 indicate respectively pointers and graduated dials associated with the screws and the frame, whereby previous settings of the rolls may be repeated in the event changes are made by reason of the treatment of varying substances.

The driving means for the various rolls may comprise the main driving pinion 59 which is fixed to the main driving shaft 60, which shaft extends across the back of the machine and is adapted to receive rotational movement from any suitable source of power, for example, a power driven pulley, sprocket or gear 6!. If desired, a motor may be connected directly with the main drive shaft. The power-pinion 59 meshes with a gear 62 which is fixed on the shaft of roll 9, and gear 62 in turn drives the gears 63 and 39 of rolls 8 and ill, respectively. Gear 63 meshes also with a gear 64 on the shaft of roll 7 and a second fixed gear 65 on said shaft drives a gear 66 which is fixed on the shaft of roll 6. The gear train just described preferably is duplicated on the side of the machine opposite to that illustrated by Fig. 1. The quickacting roll displacing means and the micrometric adjustment means also are duplicated on the opposite side of the machine, as are also the bearing structures for all the rolls.

The completed machine includes a lubricating system, gear covers or dust shields, cooling means forthe rolls, etc., all of which is considered not pertinent to the present invention and is therefore not illustrated or described.

The operation of the machine is desc ibed as follows. With the gear train driven by means of a motor or other suitable power source, the substance to be treated is placed in the trough formed between the two feed rolls 6 and 1. As these rolls rotate in the directions indicated by the small arrows, the substance (usually a liquid or semi-solid) is transferred by roll .1 onto roll 8, the transferring being continued by rolls 9 and I until. finally the substance is removed from roll H) by means of the scraper or remover I2. While the machine is thus operating, the various hand wheels may be actuated to micrometrically adjust-the force of the rolls upon one another so that the substance treated will be crushed and mixed uniformly along the full length of the rolls. The levers will be in the positions shown, with their adjusting screws 52 in contact with their respective stops 53.

Should it thereafter be necessary to clean the rolls, the operator grasps the levers 5|, which move in pairs, and elevates them through an arc of about 90 degrees, beginning with the upper pair, so that the top roll will first be lifted off of the next roll 9. Then the next pair of levers is elevated by the operator, to lift the roll 9 from contact with roll 8. As the throw of the cams associated with screw 28 is less than the throw of the corresponding cams 43 and 44 of the upper roll displacing unit, the roll 9 will not, when displaced, contact the upper roll l0. Similarly, ac-

- tuation of the third or lowermost pair of levers 5|. will cause the roll 8 to be lifted from the feed roll 1 without moving it into contact with the previously displaced roll 9. If necessary, the handwheels 20 may be operated to separate the feed rolls 6 and 1. While all the rolls are thus separated or spaced apart, the driving gears remain in mesh sufficiently to rotate the rolls, and the rolls may then be wiped clean as they idle under the power of the driving means. After the rolls are cleaned, the feed rolls 6 and 'i may be returned to the feeding position, and all the transfer rolls moved quickly and accurately to the original setting by means of the three pairs of levers 5!, without disturbing the micrometric adjustment of the screws 21, 28 and 29. Thus the machine is replaced in service with a minimum loss of time and effort.

As stated before, the rolls are protected from injury andextreme mal-adjustment, by means of the stops or limiting collars M and 42 which -are normally fixed upon the adjusting screw shafts in slightly spaced relationship at opposite ends ofthe adjusting screw nuts, 32.

It is to be understood that various modifications and changes in the structural details of the device may be made, within the scopeof the appended claims, without departing from the spirit of the invention.

What is claimed is:

1. The combination of a frame, a plurality-of superposed rolls having bearing ends, means supporting said bearing ends comprising pairs of circular bearing supports mounted for rotational movement relative to the frame, cooperative bearings associated with said supports and hav 'ing their centers offset relative to the axes of rotation of the bearing supports, the bearing ends of the rolls being received in the said cooperative bearings, means for rotating certain of the bearing supports in unison, and associated means for rotating the bearing support, individually, the true centers of corresponding bearing supports being offset relatively, with the axes of the superposed rolls lying normally in a. single upright plane.

2. In a device of the class described, the combination of a frame, a plurality of rolls having bearing ends, means supporting said bearing ends comprising bearing supports mounted for rotational movement relative to theframe, alternate ones of said bearing supports being reversed and having their centers offset relatively, cooperative bearings for the roll bearing ends associated with said supports and having their axes offset relative to the centers of the bearing supports, the axes of said bearings for the roll bearing ends being disposed substantially in a single plane,

means for rotating certain ones of the bearing supports in unison for displacing the rolls bodily, and relatively slow acting means operative for rotating the bearing supports individually.

3. In a device of the class described, the combination of a frame, a plurality of rolls having bearing ends, means supporting said bearing ends comprising bearing supports mounted for rota tional movement relative to the frame, alternate ones of-said bearing supports being reversed and having their centers offset relatively; cooperative bearings for the roll-bearing ends associated with said supports and having their axes offset relative to the centers of the bearing supports, the axes of said bearings for the roll bearing ends being disposed substantially in a single plane,

means for rotating certain ones of the bearing supports in unison for displacing the rolls bodily, and relatively slow acting means operative for rotating the bearing supports individually, and

means associated with said individually operative ration for reception of the bearing end of the roll, the perforation of said support being eccentric to the center of the support, a screw having a handle and threads, and means for mounting the screw upon the frame in substantial parallelism with a plane which passes through the center of the support and the axis of the bearing perforation, a nut mounted for movement with the bearing support and disposed for engaging the threads of the screw whereby rotation of the screw effects a rotation of the bearing support, and means for bodily shifting the screw mounting means substantially longitudinally, independently of actuation of the screw handle. v

5. In combination, a frame member, a roll hav ing a bearing end, support means mounted. ro-

tatably relative to the frame member for supporting said bearing end and comprising a perforation for reception of the bearing end of the roll, the perforation of said support being eccentric to the center of thesupport, a screw having a handle and threads, and means for mounting the screw upon the frame in substantial parallelism with a plane which passes'through the center of the support and the axis of the bearing perforation, a nut mounted for movement with the bearing support and disposed for engaging the threads of the screw whereby rotation of the screw effects a rotation of the bearing support, and means including a rotatable cam for bodily shifting the screw mounting means substantially longitudinally, independently of actuation of the screw handle.

6. In combination, a frame member, a roll having a bearing'end, support .means mounted rotatably relative to the frame member for supporting said roll and comprising a perforation for reception of the bearing end of the roll, the

perforation of said support being eccentric to the center of the support; a screw having a shank, a

handle, and threads, a cam mounted for rotation relative to the frame and provided with means for rotating the cam, a bearing box associated with the cam and having a bore therein for reception of the screw shank, meansprecluding longitudinal movement of the shank in the bearing box while permitting rotation of the shank therein, the support, the cam, and the bearing box being so related that the screw extends in substantial parallelism with a plane which passes through the center ofthe support and the axis of the. aforesaid perforatiog, a nut engaging the screw threads and means for mounting the nut upon the rotatable supp rt.

7. In combination, a frame member, a roll} having a bearing end, sup means mounted rotatably relative to the frame member for supporting said roll and comprising a perforation for reception of the bearing end of the roll, the perforation of said support being eccentric to the center of the support, a screw having a shank, a 5

handle, and threads, a cam mounted for rotation relative to the frame and provided with means for rotating the cam, a bearing box associated with the cam and having a bore therein for reception of the screw shank. means precluding longitudinal movement of the shank in the bearing box while permitting rotation of the shank therein, the support, the cam, and the bearing box being so related that the screw extends in substantial parallelism with a plane which passes 1 through the center of the support and theaxis of the aforesaid perforation, a nut engaging the screw threads and means for mounting the nut upon the rotatable support, and means for limiting the travel of the screw through the nut so as 2 to allow onlya slight rotation of the rotatable support by reason of rotational movement of the screw.

8. A machine of the class described, comprising in combination, a frame member, a roll hav- 2 perforation of said support means being eccentric 3 to the true center of the support means, a screw having a shank, a handle, and threads, a nut carried by the support means and operatively engaging the threads of the screw, and means upon the frame including an eccentric mounting 3 for the screw shank in position to rotate the roll support means upon rotational movement of the screw, the eccentric mounting being adapted to advance and retract the screw longitudinally, and, to assume a dead-center position locking the 4 screw at one limit of its longitudinal travel.

9. A machine comprising in combination, a frame member, a roll having a bearing end,-sup.- portmeans for the roll mounted rotatably relative to the frame member, said support means having a perforation for rotatably receiving thebearing end of the roll, the perforation of said support means being eccentric to the true center of the support means, a screw having a shank, a

' handle, and threads, a nut carried by thesupport I perative engaging screw threaded means onthe adjusting memberand the bearing means for adjusting the position of the bearing means by rotation of the adjusting member, a rotatable cam shaft supported upon the frame a substantially perpendicularly to the axis ofrotation of the rotatable adjusting member, a cam on said shaft, a box having a circular bore rotatably housing said cam, a bearing carried by 1 said box and receiving the rotatable adjusting Hmember, and means-for normally precluding longitudinal movement of the adjusting member in the last mentioned bearing.

11. In a machine of the class described, the 1 combination of a frame, a roll bearing means mounted upon the frame for shifting movement,

a screw threaded nut carried by and -movable with the roll bearing means, a screw comprising a threaded end engaging the threads of the nut, a shank portion, and a manipulating means on the screw, a rotatable shaft supported upon the frame substantially perpendicularly to the screw, a circular disc eccentrically mounted upon said shaft, a bearing box having a circular bore rotatably supporting said disc and a second bore rotatably supporting the screw shank, means for rotating the eccentrically mounted disc within the first mentioned bore-of the bearing box,

and means for normally precluding longitudinal movement of the screw shank through the second mentioned bore of the bearing box.

12. In a machine of the class describedthe combination of a frame, a transfer roll rotatably mounted upon the frame, a second roll and shiftable bearing means therefor whereby said second roll may be moved to and from a working position with respect to the first roll, a rotatable adjusting member for said shiftable bearing, means, cooperative engaging screw threaded means on the adjusting member and the bearing means for varying the position of the bearing means by rotation of the adjusting member, a ro- .tatable cam shaft supported upon the frame substantially perpendicularly to the axis of rotation of the adjusting member, a cam on said shaft having a toe and a heel, a box having a circular bore rotatably housing said cam, a bearing carried by said box and receiving the rotatable adjusting member, means for normally precluding longitudinal movement of the adjusting member in the bearing of the box, the heel and toe of the cam being so related to the box bearing as to assume a dead center relationship with the axis of the adjusting member when the rolls are disposed in working position.

13. In a roller mill having a frame and a series of superposed rolls supported thereon with their axes in a single upright plane, the combination of pairs of supports for the opposite ends of the rolls, said supports being circular and rotatable relative to the frame, with the centers of the roll supports staggered and lying at opposite sides of the plane of the roll axes, and means for rotating adjacent roll supports in opposite directions of rotation for spacing the rolls apart.

14. In a roller mill having a frame and a series of superposed rolls supported thereon with their axes in a single upright plane, the combination of pairs of supports for the opposite ends of the rolls, said supports being circular and rotatable relative to the frame, with the centers of the roll supports staggered and lying at opposite sides of the plane of the roll axes, and means for rotating adjacent roll supports in opposite directions of rotation for spacing the rolls apart, said means including a series of quick-acting eccentric devices each connected to a roll support and movable to a dead-center position at which the roll support is locked against accidental rotation.

15. In a roller mill having a frame and a series of superposed rolls supported thereon with their axes in a single upright plane, the combination of pairs of supports for the opposite ends of the rolls, said supports being circular and rotatable relative to the frame, with the centers of the roll supports staggered and lying-at opposite sides of the plane of the roll axes, andmeans for re,- tating adjacent roll supports in opposite directions of rotation for spacing the rolls apart, said means including a series of quick-acting eccentric devices each connected to a roll support and movable to a dead-center position at which the roll support is locked against accidental rotation, and a second means for rotating the roll supports while the other roll su port rotating means means along an are upon rotation of said shaft in opposite directions, and a cam device movable to a dead-center position and operatively connected with the adjustment shaft to shift it longitudinally independently of its rotational movement, the dead-center position of the cam device serving to lock the shaft against longitudinal shifting in one direction.

17. A machine of the character described comprising in combination, a frame member, a roll having a bearing end, support means for the roll mounted rotatably relative to the frame member, said support means having a bore for rotatably receiving the bearing end of the roll, the bore of said support means being eccentric to the true center of the support means, a screw having a shank, a handle, and threads, a nut carried by the support means and operatively engaging the threads of the screw, the nut being rockably mounted at one side of the axis of rotation of the support means, a selectively shiftable bearing means on the frame member snugly embracing the screw shank for rotational movement of said shank with a close bearing fit, and means precluding lengthwise movement of the screw in said bearing means.

18.- In a device of theclass described, the com bination of a frame, a plurality of rolls having bearing ends, means supporting said bearing ends comprising bearing supports mounted for rotational movement relative to the frame, alternate ones of said bearing supports being reversed and having their centers offset relatively, co-

operative bearings for the roll-bearing ends associated with said supports and having their axes offset relative to the centers of the bearing supports, the axes of said bearings for the roll bearing ends being disposed substantially in asingle plane, means for rotating certain ones of the bearing supports in unison for displacing the rolls bodily, and relatively slow acting means operative for rotating the bearing supports individually, each including a screw shaft and a I of pairs of supports for the opposite ends of the rolls, said supports being circular and rotatable relative to the frame, with the centers of the roll supports staggered and lying at opposite sides of the plane of the roll axes, and means for rotating adjacent roll supports in opposite directions of rotation for spacing the rolls apart, said means,

including a series of quick-acting eccentric devices each connected to a roll support and mov-.

- able to a dead-center position at which the roll support is locked against accidental rotation, and relatively slow acting means manipulatable to impart opposite directions of rotation to adjacent bearing supports upon actuation of said slow acting means in a common manner and direction to eifect roll contact adjustments, and gearing for driving the rolls and tending to rotate each roll support in a direction opposing roll advancing movement of said slow acting means.

20. In a roller mill having a frame and a series of superposed rolls supported thereon with their axes in a single upright plane, the combination of pairs of supports. for the opposite ends of the rolls,isaid supports being circular and rotatable relative to the frame, with the centers of the roll supports staggered and lying at opposite sides of the plane of the roll axes, and means including a series of eccentrics each having a different throw value, for rotating adjacent roll supports various distances in opposite directions of rotation for spacing the rolls apart.

21. In a roller mill having a frame and a series of superposed rolls supported thereon with their axes in a single upright plane, the combination of pairs of supports for the opposite ends of the rolls, said supports being circular and rotatable relative to the frame, with the centers of the roll supports staggered and lying at opposite sides of the plane of the roll axes, and means for rotating adjacent roll supports in opposite directions of rotation for spacing the rolls apart, said means including a series of quick-acting eccentric movement, a rotatable adjusting member for,

each of the bearing means, cooperative engaging screw threaded means on each adjusting member and its associated bearing means for adjusting the position of the bearing means by rotation of the adjusting members, a series of rotatable cam shafts each supported by the frame substantially perpendicularly to the axis of rotation of a rotatable adjusting member, a cam on each shaft, each of said cam having a different throw value, a box having a circular bore rotatably housing each cam, a bearing carried by each box and receiving one of the rotatable adJusting members, and means for normally precluding longitudinal movement of the adjusting member in'the last mentioned bearing.

. 23. A roller mill comprising a frame and a pluing the rolls in substantial parallelism, and means for shifting said roll supporting bearings and the rolls supported thereby, to alter the spac-' ing between the rolls, said means comprising a rotatable eccentric for each .roll and connecting means between the eccentrics and the roll sup porting bearings for translating rotational movement of theeccentrics into shifting movement of the roll supporting bearings, the eccentrics for the different rolls having different throw values, assuring diifering extents of roll supporting bearing shiftability upon rotation of the eccentrics through substantially equal arcs of rotation.

, 24, vA roller mill comprising a frame and a plurality of rotatable rolls, roll supporting bearings shiftably mounted upon the frame for supporting the rolls in substantial parallelism, and means for shifting said roll supporting bearings and the rolls supported thereby, to alter the spacing between the rolls, said means comprising a rotatable eccentric for each roll and connecting means between the eccentrics and the roll supporting bearings for translating rota-.

tional movement of the eccentrics into shifting movement of the roll supporting bearings, the eccentrics for the different rolls having different throw values, assuring differing extents of roll supporting bearing shiftability upon rotation of the eccentrics through substantially equal arcs of rotation, and means for rotating the eccentrics toward and from dead-center holding relationship to the roll supporting bearings.

25. A roller mill comprising a frame and a plurality of--v rotatable rolls, roll supporting bearings shiftably mounted upon the frame for supporting the rolls in substantial parallelism, and means for shifting said roll supporting bearings and the rolls supported thereby, to alter the spacing between the rolls, said means comprising a rotatable eccentric for each roll and connections between the eccentrics and the roll supporting bearings for translating rotational movement of the eccentrics into shifting movement of the roll supporting bearings, the eccentrics for 1 the different rolls having different throw values,

assuring differing extents of roll supporting bearing shiftability upon rotation of the eccentrics through substantially equal arcs of rotation,

and comparatively slow acting means for shifting said roll supporting bearings while the cocentrics remain in a state of rest.

26. A roller mill comprising a frame and a plurality of rotatable rolls, roll supporting bearings shiftably mounted upon the frame for supporting the rolls in substantial parallelism, and

means forshifting said roll supporting bearings and the rolls supported thereby, to alter the a spacing between the rolls, said means comprising a rotatable eccentric for each roll and connec-' tions between the eccentrics and'the roll sup porting bearings for translating rotational movement of the eccentrics into shifting movement ofthe roll supporting bearings, the eccentrics for the different rolls having different throw values, assuring difieringextents of roll supporting bearing shiftability upon rotation of, the ec-' centrics through substantially equal arcs of rotation, and additional roll supporting bearing shifting means operative individually upon the bearings at opposite ends of the rolls for equalizing the force of roll contact at-opposite ends of the contacting rolls.

4 CLARENCE R. RECHTIN.

RICHARD JANTSCH. 

